The Fortis says on the back: Water Resistant 20ATM/200M.
The Luminox says on the front and back: 200M Water Resistant
Both have screw down crowns.
I'm inclinded to think that if I'm going swimming or snorkeling in salt water, I'd be better off using the Luminox, just because it seems like it's more suited to that purpose. I dunno.
I should have just bought a Timex to go swimming with...not a $175 Luminox. But it was such a deal! Or at least it felt that way. Marked down from $329.
While we're away on vacation I'm going to look around at watches and see if any of the islands have something I like that's a good deal. Something I can buy that'll be a momento of our trip. Imagine I get something and then come home to find it at the TJMaxx on clearance? LOL.